A unit device such as a server is provided with a fan for cooling internal heat generating components such as a central processing unit (CPU). An effective way to cool the heat generating components efficiently is to hit most of an airflow created by the fan against the heat generating components.
However, in the unit device, electronic components such as memories and wiring substrates are arranged so densely that it is difficult to hit the airflow against the heat generating components. This problem is particularly remarkable in the case where a plurality of heat generating components is provided in a single unit device.
The techniques related to the present application are disclosed in Japanese Laid-open Patent Publication Nos. 2007-133712 and 06-177566.